'51 M37 rear mail oil seal replacement

[asstor]

Hi all,

I just purchased a 1951 M37 (nicknamed 'Mater by my 9 year old) and discovered to my horror (or should that be - I should have known this was coming...?) that the engine front and rear main oil seals both leak badly. Replacing the front seal is no problem, however - do I need to drop the crank to replace the rear seal or can I get to it if I pull the flywheel off? It is the split type.

Thanks in advance for any replies

Louis

 

[asstor]

I'll answer my own question for anyone else's benefit. I found the answer on another forum and will post that reply I received here as follows:

You will need to pull the pan, and flywheel housing bottom cover. Loosen all the main bearing caps somewhat so the crank can drop slightly downward. Remove the rear main cap completely, half the seal will be on the cap. Use a small blunt tipped punch against the end of the upper seal half. Push upward and it will push right around the crank, grasp the other end of the seal to pull it out. You will find "Y" shaped rubber seals on both sides of the cap, remove them and clean all surfaces thoroughly.

Hopefully this will help someone else with the same question.

Cheers.

 

[timmmaaa06]

Clutch oil Leak

Hi My name is Tim we had a leak in the front of the oil pan. I replaced all the gaskets on the pan and now have bigger leaks in the back of the pan. I do not know if it is between the clutch and engine or what but the oil is dripping down and inside the clutch housing is driping of oil the two rubber seals that are infront of the clutch and back of the pan look to be in good shape. I have been at this for three days I dont know where is is coming from. it seam to really drip once it gets warmed up. thank you for your help

 

[timmmaaa06]

by the way I have a 1953 dodge power wagon m37 6 cylinder flathead

 

[plym49]

I'll answer my own question for anyone else's benefit. I found the answer on another forum and will post that reply I received here as follows:

You will need to pull the pan, and flywheel housing bottom cover. Loosen all the main bearing caps somewhat so the crank can drop slightly downward. Remove the rear main cap completely, half the seal will be on the cap. Use a small blunt tipped punch against the end of the upper seal half. Push upward and it will push right around the crank, grasp the other end of the seal to pull it out. You will find "Y" shaped rubber seals on both sides of the cap, remove them and clean all surfaces thoroughly.

Hopefully this will help someone else with the same question.

Cheers.

Pull the rear cap but you do not need to drop the crank. The old seal will roll out exactly as described. Anyway, you cannot get the crank to hang unless you pull the tranny as it will be hanging on the pilot bushing/input shaft. Yes, you can pick up a few thousandths this way but it is not needed.

 

[rosco]

You can roll the new, top half of the seal in, just as the old one came out. It seems like there was a kit thing to aide in the instillation. It was a small cable wire chinese puller thing, that woud help to pull the new one into place. When you install the bottom cap, with the new seal in place, care should be taken that there is not seal pieces that squish out, to hold the bearing cap from seating. Use a razor blade to trim the seal flush, but don't trim it low either..

I have built several of those engines. Sometimes i get the seal into place and never have a problem, and the next time, I don't get around the block, and its leaking. The old Internationals had the same kind of seals - same problems too.

 

[Oldvw2]

Hi all,

I just purchased a 1951 M37 (nicknamed 'Mater by my 9 year old) and discovered to my horror (or should that be - I should have known this was coming...?) that the engine front and rear main oil seals both leak badly. Replacing the front seal is no problem, however - do I need to drop the crank to replace the rear seal or can I get to it if I pull the flywheel off? It is the split type.

Thanks in advance for any replies

Louis

Another thought: if your truck still has the fording equipment make sure that the valve is in the proper position. I believe that running with the crankcase vent valve closed can pressurize the crankcase to the point that the main seals will leak. You can see the fording valve on Cabell's (CGarbee) M37 page here: http://www.garbee.net/~cabell/Otherfollks/mwo/FordingB.jpg

Chad

 

[plym49]

You can roll the new, top half of the seal in, just as the old one came out. It seems like there was a kit thing to aide in the instillation. It was a small cable wire chinese puller thing, that woud help to pull the new one into place. When you install the bottom cap, with the new seal in place, care should be taken that there is not seal pieces that squish out, to hold the bearing cap from seating. Use a razor blade to trim the seal flush, but don't trim it low either..

I have built several of those engines. Sometimes i get the seal into place and never have a problem, and the next time, I don't get around the block, and its leaking. The old Internationals had the same kind of seals - same problems too.

It's called a Sneaky Pete, a tool to install the upper rear main rope seal with the crank in place. The tool is a length of flexible steel cable with a t handle at one end and a small corkscrew on the other. To remove the old upper rope seal, you thread the cork screw into one end of the seal and you pull it out. To install a new one, you slip the tool up and over the crank and thread it into one end of the new rope seal. You lube the rope seal with some oil and pull it right into place.

As far as trimming the ends, use a razor blade and the edges should be a little proud of the face of the block with a little 'mountain' in the center. That way when you tighten the cap it squished down flat and seals with the lower rope seal, face to face.

 

[dwayneski]

front seal

just purchased a 1951 M37 (nicknamed 'Mater by my 9 year old) and discovered to my horror (or should that be - I should have known this was coming...?) that the engine front and rear main oil seals both leak badly. Replacing the front seal is no problem, however - do I need to drop the crank to replace the rear seal or can I get to it if I pull the flywheel off? It is the split type.

My sons real seal is leaking but not the front. should we rplace it and how did you do it?